For instance, if I hear the clock with great attention, I will not, perhaps, see anything although my eyes may be open, showing that the mind was not attached to the seeing organ, while it was to the hearing organ. But the perfected mind can be attached to all the organs simultaneously. It has the reflexive power of looking back into its own depths. This reflexive power is what the Yogi wants to attain; by concentrating the powers of the mind, and turning them inward, he seeks to know what is happening inside. There is in this no question of mere belief; it is the analysis arrived at by certain philosophers. Modern physiologists tell us that the eyes are not the organ of vision, but that the organ is in one of the nerve centres of the brain, and so with all the senses; they also tell us that these centres are formed of the same material as the brain itself. The Sankhyas also tell us the same thing The former is a statement on the physical side, and the latter on the psychological side; yet both are the same. Our field of research lies beyond this.